Stabilized polydiazo-phthalocyanines



Patented May 16, 1944 UNITED STATES PATENT {OFFICE STABILIZED POLYDIAZO-PHTHALO CYANIN ES Norman Hulton Haddock, Blackley, Manchester,

England, assignor to Imperial Chemical Industries Limited, a corporationof Great Britain No Drawing. Application May 19, 1942, Serial No.443,668. In Great Britain May 25, 1939 Claims.

vention will appear as the description proceeds.

This application is a continuation-in-part of my copending applicationsSerial No. 335,871, filed May 17, 1940, and Serial No. 408,931, filedAugust 30, 1941. The former of these was issued April 21, 1942, asPatent No. 2,280,072.

In my parent applications I have described a novel method for producingmetal-free and metallic tetra-amino-phthalocyanines. According to mysaid invention tetra-amino-phthalocyanines are prepared by reducing thecorresponding tetra-nitro-phthalocyanines by the aid of special reducingagents such as sodium sulfide, sodium hydrogen sulfide, sodiumdisulfide, stannous chloride or sodium hydrosulfite.

As typical tetra-nitro-phthalocyanines which may be economicallyemployed for this purpose, there were mentionedcopper-tetra-(4)-nitrophthalocyanine, copper-tetra- (3)-nitro-phthalocyanine, mixtures of these; other metallictetranitro-phthalocyanines for instance those of cobalt, nickel,aluminum, lead or magnesium; and also metal-freetetranitro-phthalocyanine.

The tetra-amines thus obtained, in good yield, were described asgenerally green in color and insoluble in water. They are turned blue bythe action of acids, for example hydrochloric'acid, seemingly owing tosalt" formation. When subjected to the action of nitrous acid, they arereadily diazotized, and in this form are useful as intermediates, namelydiazo components, in the preparation of coloring matters.

In a similar manner, phthalocyanines having three or two diazoniumgroups may be prepared by starting with the corresponding trinitro anddinitro-phthalocyanines. prepared bysynthesizing phthalocyanines fromthe preferred metal, say copper or cobalt, on the one hand and from amixture of phthalonitrile and nitrophthalonitrile (in molal ratio 1:3 or2: 2, respectively) on the other hand. (See for instance my copendingapplication, Serial No. 390,912.) Also, by starting with atetra-nitrophthalocyanine and reducing to a tetra-amino compound butusing then a limited quantity of nitrous acid, phthalocyanine compoundscon- These in turn may be taining less than four diazo groups permolecule may be produced.

My present invention is concerned primarily with the problem ofstabilizing these polydiazo phthalocyanine compounds, whereby to obtainthe same in solid state or equally stable form suitable for handling incommerce.

It is known that aryl diazonium compounds may be converted into variousderivatives, of varying degrees of stability, which however may bedivided generally into two classes:

1. Compounds which, in neutral or acid aqueous solution, show thereactions of the diazonium ion directly upon solution. This groupcomprises-'- (a) Diazo compounds stabilized by double-salt formationwith inorganic compounds such as polyvalent metal halides orvfluoroboric acid;

(b) Diazo compounds stabilized by reaction with aryl sulfonic acids,such as naphthalene- 1,5-disulfonic acid.

II. Compounds which are stable in neutral or alkaline solution, but donot give a diazonium cation in aqueous solution except uponacidificationof the solution. This group comprises- (c) The isodiazotates or"nitrosamines;

(d) Diazoamineand diazoimino-compounds having water-solubilizing groups.

(e) Diazosulfonat'es of the formula (K. H. Saunders, The Aromatic DiazoCompounds and Their Technical Applications, London, 1936, page 30.)

The members of group II if dissolved in Water in the absence of aciddissociate into alkalimetal cations, and anions which contain thearyl-diazo radical. Treatment with acid however, converts them in situinto a diazonium salt of the acid selected, which ionizes then into a beconverted into derivatives of either of the above two types I and II.

This result was by no means readily foreseeable, inasmuch as we havefound that the socalled amino-phthalocyanines prepared fromamino-phthalic acid derivatives (for example by heatingamino-phthalimide with urea and cuprous chloride), do not diazot'ize,and therefore cannot form the various stable polydiazonium compounds ofthis invention.

The diazotized amino-phthalocyanines have valuable afimity forcellulosic fiber. Their conversion derivatives of this invention arestable in solid form, and possess various degrees of stability when insolution. This invention, therefore, opens the field to a new series ofphthalocyanine compounds which may be used in the arts of dyeing andprinting cellulosic fiber.

For the sake of simplifying the discussion, the tetradiazo compoundswill be treated hereinafter as typical of the entire group, but itshould be understood that my invention is not limited; and may beapplied to any compound of the phthalocyanine series having from 1 to 4diazo groups per molecule.

According to my invention, the tetradiazo compounds of thephthalocyanine series obtained above may be precipitated in a formsuitable for technical handling, that is in solid state, by adding tothe solutions thereof zinc chloride,

cadmium chloride or other salt suitable for the production of doublesalts of aryl diazonium compounds, for instance cobalt chloride, ferricchloride, mercuric chloride, fluoroboric acid, etc. Alternatively, theymay be treated with naphthalene sulfonic acid or other aryl sulphonicacids which will give salts of the tetradiazo compounds sparingly enoughsoluble in water to be precipitated, e. g. naphthalene-1,5-disulionicacid, naphthalene-trisulfonic acid, benzene-sulfonic acid,phenol2,4=-disulfonic acid, 4-sulfophthalic acid, and the alkali-metalsalts of these acids.

Again, the tetradiazonium derivatives may be isolated in solid state byconverting them into the corresponding alkali-metal-isodiazotates. Thelatter I have found can be made by the usual methods employed inconverting aromatic diazonium salts into the correspondingisodiazotates. For example, the potassium tetra- (4) -iso-diazotate ofcopper phthalocyanine is prepared by adding a solution of thetetradiazonium chloride to an excess of aqueous potassium hydroxide at lC. and then adding the mixture to a large volume of concentrated aqueouspotassium hydroxide at not less thanabout 120 C.

A fourth method is to convert the tetradiazo compound into atetra-diazoimino compound by treatment with a primary or secondary aminecapable of forming diazoimino compounds with diazotized amines ingeneral and possessing water-solubilizing groups (e. g. sulfo andcarboxy groups), as typified by methyl-taurine,

N-methyl-glycine and N-methyl-anthranilic acid.

Finally, the tetradiazo compound may be treated with sodium sulfite toconvert it into a tetra-diazo sulfonate.

I have found that the above stable derivatives:

of tetradiazo-phthalocyanines, whether of the double-salt type or of anyof the other types, possess valuable properties, and may be used asintermediates for the production of phthalocyanine azo dyestuffs eitherin substance or on the fiber.

Thus, the derivatives of the active type may be applied to cellulosicfiber from aqueous bath and then developed on the fiber with variousazoic coupling components, producing violet to green and grey shades ofgood fastness properties, including outstanding fastness to washing.(See copending application of Blackshaw and Haddock, Serial No. 355,692,filed September 6, 1940, or the corresponding British Patent No.535,935.) Among the azoic coupling components suitable for this purposemay be mentioned phenol, ,B-naphthol, 2-hydroxy-3-naphthoic anilide,bis-acetoacet o-tolidide, l-phenyl- 3-methyl-5-pyrazolone, resorcinol,a-naphthol, 2:3 hydroxy naphthoic o toluidide,2-:3-hydroxynaphthoic-p-anisidide and the p-chloranilide of2-hydroxycarbazole-3-carboxylic acid. Or the diazonium salts may becoupled to said azoic coupling components in a reaction vessel,producing the corresponding pigments in substance.

Again, they may be used for developing azo colors on the fiber by dyeingor printing them onto cellulosic fiber which has been first padded, inusual fashion, with ice-color coupling components, such as p-naphthol orthe arylides of 2,3-hydroxy-naphthoic acid. It will be notedincidentally that this mode of utility is inherent also in thefreshly-prepared poly-diazonium compounds of the phthalocyanine series,that is, before conversion into the stabilized forms hereinabovediscussed.

In the case of the diazonium derivatives of the passive type variationsin application procedure well-known in the art are employed. For examplecotton cloth impregnated with an icecolor coupling component may beprinted with a paste containing an isodiazotate or diazoamino compoundof tetra-amino-copper-phthalocyanine. The coupling on the fiber is theneffected by steaming in the presence of acid vapors, e. g. acetic orformic acid. Alternatively the coupling component may be incorporatedinto the printing paste. If a solution ofthe azotizedamino-phthalocyanine is desired, a sample of the isodiazotate, forexample, may be stirred in cold concentrated hydrochloric acid toproduce it. The diazosulfonates and diazoamino compounds, however, arenot readily converted to solutions of the free diazo compounds.

Alternatively, the stable phthalocyaninediazonium compounds of thisinvention may be applied to the fiber from aqueous bath, and thentreated on the fiber with reagents and under conditions adapted todecompose the diazonium groups liberating nitrogen, producing on thefiber insoluble phthalocyanine derivatives. (See the copendingapplication. of Blackshaw and Haddock above referred to.) Green to blueshades of excellent fastness properties may thus be obtained. Thedeveloping substances selected for this purpose may be organic orinorganic compounds, and the vast field of applicable agents may beillustrated by the following: water, ethyl alcohol, potassium iodide,potassium bromide, potassium ethyl xanthate, sodium ethyl xanthate,pyridine, sodium stannite, sodium sulphite, sodium oleyl sulphate,potassium ferrocyanide, ammonia, sodium sulphide, formic acid, sodiumthiosulphate, benzoquinone, hydrazine sulphate, potassium cyanate,sodium formate,

sodium hypophosphite, sodium thiocyanate, sodium cupracyanide andalkaline formaldehyde.

In the cases of the diazoaminos and diazosulfonates, due to theirgreater stability, the decomposition proceeds most rapidly and comacidsin water lose nitrogen rapidly on warming, with the formation of greenprecipitates.

The invention is illustrated but not limited by the following examples,in which the parts are by weight.

EXAMPLE L-Zinc chloride double salt 12.3 parts of finely dividedcopper-tetra-(4)- amino-phthalocyanine (prepared as in Example 4 of myparent application, Serial No. 335,871), in the form of an aqueouspaste, are mixed with 120 parts of water and 6 parts of sodium nitrite.This mixture, cooled to 5 C., is then added to 90 parts of concentratedaqueous hydrochloric acid (sp. gr. 1.16) previously cooled to C.

The clear dark green solution thus obtained, which presumably containsthe tetradiazonimn chloride of copper-tetra-(4) -amino-phthalocyanine,may be used directly in various dyeing operations. For instance, it maybe neutralized with sodium acetate to Congo red, diluted with water to aconcentration of about 0.15%, and employed, at a temperature of 0 to 5C., to develop an azo dye upon fiber which has been padded with anice-color coupling'component such as betanaphthol or the anilide of2,3-hydroxy-naphthoic acid. For the purpose of the present invention,however, I prefer to treat this solution further to isolate adouble-salt of the poly-diazonium compound, as follows: 7

To the clear dark green solution of the tetradiazo compound aboveobtained, a solution of 25 parts of zinc chloride in 50 parts of 0.5%aqueous hydrochloric acid is added. There is formed a dark green finelydivided precipitate. This is filtered off, washed with acetone anddried. The product, a deep green powder, is a zinc chloride double salt.It is readily soluble in cold water to give a greenish blue solution.

Instead of 25 parts of zinc chloride in the above example, 35 parts ofcadmium chloride may be used, resulting in the cadmium chloride doublesalt of the azotized phthalocyanine compound. If a solution containing20 parts of fiuoroboric acid (HBF4) is employed instead, afiuoro-boricacid double salt is obtained.

' In a similar manner, the zinc-chloride or other double salts,respectively, may be obtained from the various poly-diazonium compoundsderivedfrom cobaltor nickel-tetra-(4) -amino-phthalocyanine; from.copper-, cobalt-, or nickel-tetra (3)-amino-phthalocyanine; fromcopper-, cobaltor nickel tri-(3)- and tri-(4) -aminophthalocyanine; andfrom the corresponding metal-free tetraand tri-amino-phthalocyanines.

All these products are stable when 'dry, and may be incorporated intoprinting pastes to be used for printing cotton fabric which has beenpreviously padded with an ice-color coupling component. Upon steamingunder acid condi tions, a water-insoluble a'zo dye is developed in theprinted areas. If they are printed on unpadded cotton cloth and steamedunder acid con- 'ditions, green prints are obtained which contain theproducts of decomposition of azotized aminophthalocyanines in theprinted areas.

EXAMPLE 2.-Stabili2at2'on with naphthalene-1,5 disulfom'c acid 30 partsof copper-tetra-() -amino-phthalo cyanine (prepared as in Example 3 ofmy parent application, Serial No. 335,871), as a finely milled aqueouspaste, are stirred with 20 parts of sodium nitrite and, in all, 500parts of cold Water. To this mixture (at below 10 C.) are quickly added,with stirring, 500 parts of 33% aqueous hydrochloric acid. After a fewminutes stirring a clear deep green solution of the tetradiazo compoundis obtained. The same result is obtained when the suspension oftetra-amino compound in aqueous sodium nitrite is added to the aqueoushydrochloric acid.

The above solution, which is now at a temperature of 5 C., is added to asolution of 160 parts of disodium naphthalene-1:5-disulphonate in 1200parts of Water, previously cooled to 0 C. The precipitated sulphonicacid salt is filtered OE and washed with acetone and dried. The greenprod uct issparingly soluble in water.

Similar results may be obtained by replacing the 160 parts ofdisodium-naphthalene-1,5-disulfonate, in the above example, by 190 partsof trisodiummaphthalene-trisulfonate, 185 parts oftrisodium-4-sulfophthalic acid, or parts of phenol-sulfonic acid.Instead of the sodium salts, the corresponding free acids may beemployed.

Instead of copper-tetra-( l)-amino phthalocyanine in the above example,any other of the metallic and metal-free tetraand triaminophthalocyanine compounds mentioned in Example 1 may be employed.

, The products of this type are less soluble and less stable in solutionthan the double salt-sobtained in Example 1. They may be used, however,

.in dyeing and printing according to the processes indicated in Example1.

EXAMPLE 3.Potass ium isodz'aeotate .30 parts of finely-dividedcopper-tetra-(4)- amino-phthalocyanine (prepared as in Example 2 of myparent application, Serial No. 335,871),

in the form of an aqueous paste, are mixed with 350 parts of water and150 parts of concentrated aqueous hydrochloric acid (sp. gr. 1.16). Tothe mixture at 5 C. is added a solution of 15 parts of sodium nitrite in50 parts of water. The temperature is maintained throughout at 5 C. orbelow. The dark green-diazo solution is now added to a stirred mixture,at 10 C., of 1200 parts of po- The mixture of 1600 parts of potassiumhydroxide and 400 parts of water previously heated to 120 C.

The temperatureis maintained at not less than 120 C. during theaddition. The mixture is cooled to 0.1 and the tetra-isodiazotate, insuspension, is filtered off through asbestos paper. Itis pressed undervacuum till dry. The product is a dark green powder soluble in coldwater to give a bluish green solution. Insteadof potassium hydroxide, inthe above examplaequivalent quantities of sodium hydroxide may beemployed. Instead of copper-tetra- (4)-amino-phthalocyanine as initialmaterial,

any other of the various tetra-hand triaminophthalocyanines mentioned inExample 1 may be substituted.

The products of this example may be applied most advantageously byprinting on cotton cloth in the form of an alkaline, thickened printingpaste. Said prints may be after-treated to decompose the isodiazotate bysteaming under acid conditions (e. g. acetic, formic acid), or byboiling with aqueous solutions of the reagents indicated in copendingapplication of Blackshaw and Haddock Serial No. 355,692 (later replacedby copending applications Ser. Nos. 444,106 and 444,107 of the sameinventors), or with dilute aqueous acids or acid salts. The paste may beprinted on cloth, which has been impregnated with an alkaline solutionof an azoic coupling component, such as an arylide of beta-oxynaphthoicacid and dried. If this print is then steamed under acid conditions (e.g. acetic, formic acid), coupling on the fiber takes place.

Furthermore, printing pastes may be prepared, which contain alkali, theisodiazotate of one of the various amino-phthalocyanines abovementioned, an ice-color coupling component and a thickener. Such pastes,when printed on cloth and steamed under acid conditions, or when passedinto an aqueous bath containing weak acids (e. g. acetic acid) or acidsalts (e. g. sodium bichromate), form the dye on the fiber and yieldgreen to brown prints.

Dyeings by one or the other of the methods disclosed in copendingapplication of Blackshaw and Haddock Serial No. 355,692, may be made bytreating these isodiazotates in the cold with aqueous acid (e. g.concentrated hydrochloric acid), which decomposes the isodiazotate andyields an aqueous solution of the normal diazonium compound.

EXAMPLE 4.Diazoimino compound 30 parts ofcopper-tetra-(4)-amino-phthalocyanine are azotized as described inExample 3. This deep-green solution obtained is added slowly withstirring to a solution containing 17 parts of N-methyl-glycine and 650parts of sodium carbonate in 9500 parts of water at -5 C. After stirringone hour, the product is isolated by salting with about 900 parts ofsodium chloride, filtering and drying. The product is soluble in Waterand is very stable.

In lieu of the 1'? parts of N-methyl-glycine in the above example, 28parts of N-methyl-anthranilic acid or 27 parts ofbeta-(N-methylamino)-ethyl-sodium sulfonate may be used,

with similar results.

Other amino compounds usable for the same purpose are pipecolinic acid,N-methyl glucamine, N-ethyl--sulfo-anthranilic acid.

In lieu of the phthalocyanine compound specified as initial material inthe above example, parts of copper-tetra- (3) -amino-phthalocyanine, 40parts of copper-tri-(4) -amino-phthalocyanine, 30 parts ofnickel-tetra-(4)aminophthalocyanine, or an equivalent proportion of anyother of the metallic and metal-free phthalocyanines named under Example1, may be employed.

The products may be applied to the fiber by converting an aqueousalkaline solution thereof to a printing paste with a suitable thickener(such as gum tragacanth or starch) and printing on cotton cloth or clothimpregnated with an alkaline solution of a substantive ice-colorcoupling component, followed by an acid steaming in the known manner,soaping and drying. Alternatively an ice-color coupling component may beincorporated in the alkaline printing paste; the paste is then printedon cotton cloth, steamed under acid conditions, soaped and dried.

EXAMPLE 5.-Diazo-sulfonate 30 parts ofcopper-tetra-(4)-amino-phthalocyanine are aZotiz-ed as described inExample 3. The deep-green solution obtained is added slowly withstirring to a solution of 650 parts of sodium carbonate and 21.6 partsof sodium bisulfite in 9500 parts of water at 0-5 C. After stirring twohours, the diazo-sulfonate is isolated by adding about 900 parts ofsodium chloride, filtering,- and drying. The product is soluble in waterand very stable.

In lieu of the tetramino phthalocyanine compound above specified, anyother of the tetraand triamino-phthalocyanines listed under Example 1may be employed in equivalent proportion (based on the number of aminogroups).

The products thus obtained are water-soluble and stable. They may beused for printing cotton fabric in the same manner as outlined underExample 4.

t will be clear that by this invention a new series of compounds arebrought into existence which are characterized by the valuable shadesand light-fastness of the phthalocyanine series of compounds; by theirafiinity for cotton fiber; and by their capacity to be applied theretofrom aqueous solution or from a thickened aqueous printing paste.

As many apparently widely different embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that I do not limit myself to specific embodiments except asdefined in the appended claims.

Subject matter disclosed above and not included in the scope of thesubjoined claims is being claimed in the copending applicationshereinabove referred to as Wellas in my copending application Serial No.443,669 of even filing date herewith.

I claim:

1. A polydiazonium compound of the phthalocyanine series, stabilized indry form by reaction with an inorganic compound selected from the groupconsisting of polyvalent-metal halides and fluoroboric acid, saidpolydiazonium compound being characterized by its solubility in waterand its direct dissociation therein to liberate a phthalocyaninepolydiazonium cation.

2. A tetradiazonium compound of the phthalocyanine series, stabilized indry form by reaction with an inorganic compound selected from the groupconsisting of polyvalent-metal halides and fiuoroboric acid, saidtetradiazonium compound being characterized by its solubility in waterand its direct dissociation therein to liberate a phthalocyaninediazonium cation.

3. A tetradiazonium derivative of the phthalocyanine series, stabilizedin dry form by complex salt formation with a polyvalent metal halide.

4. The zinc chloride double salt of copper tetradiazo phthalocyanine.

5. The zinc chloride double salt of metal-free tetradiazophthalocyanine.

NORMAN HUL-TON HADDOCK.

